The invention relates generally to methods and apparatus for drawing or collecting blood or other biological fluid from a patient and thereafter dispensing the biological fluid in aliquots for analytical testing. More specifically, the present invention relates to a one-piece disposable apparatus including all of the features needed to draw such fluid and thereafter dispense the fluid.
The separation and analysis of chemical substances provides valuable quantitative and qualitative data for use by researchers and health care providers. Many assaying techniques have been developed which utilize sensitive chemical tests and sensitive instruments to detect both normal and abnormal components of biological fluids such as blood, urine and spinal fluid. In particular, the analysis of samples of these fluids reveals information which is critical to the proper diagnosis and treatment of many disorders. To perform such an analysis, a biological sample is typically withdrawn from the patient into a test tube or vacuum draw collection tube. The biological sample may be subjected to centrifugation. Then the biological sample is dispensed, in suitable aliquots, for testing. In the example of withdrawing blood from a patient, centrifugation separates the serum from the red blood cells and, thereafter, the amount of serum protein, protein-bound iodine, sodium, triglycerides, salicylate, uric acid and the like may all be determined through the analysis of the blood components.
After a biological sample is withdrawn from a patient into a test tube or collection tube, a technician must dispense aliquots or small quantity samples from the test tube. The test tube, of course, is initially sealed to prevent (a) contamination of the sample by ambient constituents and (b) to prevent substances in the sample from entering the atmosphere and/or adversely affecting the technician. Upon removing the conventional stopper from a test tube, the sample is again subject to possible contamination and a phenomenon known as aerosoling occurs. Aerosoling is the expulsion into the air, in the vicinity of the test tube, of minute quantities of the contents of the test tube and is caused by the force of removal of the stopper from the test tube. The removal of the stopper subjects the technician to the risk of exposure to whatever virus, bacteria or the like is carried in the biological sample.
The concern about exposure to the HIV virus has resulted in the adoption of numerous safety precautions in connection with the handling of biological fluids including products for dispensing biological fluids from a test tube without the need for removal of the stopper.